docs: def update_header(self):
          """
          Updates header to edffile struct
          """
          set_technician(self.handle, du(self.technician))
          set_recording_additional(self.handle, du(self.recording_additional))
          set_patientname(self.handle, du(self.patient_name))
          set_patientcode(self.handle, du(self.patient_code))
          set_patient_additional(self.handle, du(self.patient_additional))
          set_equipment(self.handle, du(self.equipment))
          set_admincode(self.handle, du(self.admincode))
          if isinstance(self.gender, int):
              set_gender(self.handle, self.gender)
          elif self.gender == "Male":
              set_gender(self.handle, 0)
          elif self.gender == "Female":
              set_gender(self.handle, 1)
  
          set_datarecord_duration(self.handle, self.duration)
          set_number_of_annotation_signals(self.handle, self.number_of_annotations)
          set_startdatetime(self.handle, self.recording_start_time.year, self.recording_start_time.month,
                            self.recording_start_time.day, self.recording_start_time.hour,
                            self.recording_start_time.minute, self.recording_start_time.second)
          if isstr(self.birthdate):
              if self.birthdate != '':
                  birthday = datetime.strptime(self.birthdate, '%d %b %Y').date()
                  set_birthdate(self.handle, birthday.year, birthday.month, birthday.day)
          else:
              set_birthdate(self.handle, self.birthdate.year, self.birthdate.month, self.birthdate.day)
          for i in np.arange(self.n_channels):
              set_samplefrequency(self.handle, i, self.channels[i]['sample_rate'])
              set_physical_maximum(self.handle, i, self.channels[i]['physical_max'])
              set_physical_minimum(self.handle, i, self.channels[i]['physical_min'])
              set_digital_maximum(self.handle, i, self.channels[i]['digital_max'])
              set_digital_minimum(self.handle, i, self.channels[i]['digital_min'])
              set_label(self.handle, i, du(self.channels[i]['label']))
              set_physical_dimension(self.handle, i, du(self.channels[i]['dimension']))
              set_transducer(self.handle, i, du(self.channels[i]['transducer']))
              set_prefilter(self.handle, i, du(self.channels[i]['prefilter']))